We propose to determine the role of human and rabbit keratocytes in the synthesis of the components of the corneal stromal matrix. For these purposes, a method of obtaining cells from the corneal stroma in high yield has been developed, allowing to avoid problems related to "in vitro" senescence. We will concentrate on the simultaneous study of the synthesis and characterization of collagen and proteoglycans by keratocytes in culture. Investigation of different metabolic states of cells in culture may parallel observations in developing or regenerating corneal stroma. Methods to be used in our study include the use of standard histological techniques and cryogenic storage, radioactive precursors of collagen and proteoglycans, cell fractionation, preparative and density gradient centrifugation, specific enzymatic digestions, column and paper chromatography and polyacrylamide gel electrophoresis. We hope these studies will fill a gap in the available information on the mechanism of transparency and opacification in the human cornea. This project may contribute to the understanding of the function of the keratocyte and the possible role of the regulation of the synthesis of macromolecules in the maintenance of corneal transparency.